U.S. patent application number 14/646575 was filed with the patent office on 2015-11-12 for single-phase induction motor.
This patent application is currently assigned to Whirlpool S.A.. The applicant listed for this patent is Whirlpool S.A.. Invention is credited to Aleandro Amauri de Espindola, Flavio J.H. Kalluf.
Application Number | 20150326082 14/646575 |
Document ID | / |
Family ID | 49884832 |
Filed Date | 2015-11-12 |
United States Patent
Application |
20150326082 |
Kind Code |
A1 |
Kalluf; Flavio J.H. ; et
al. |
November 12, 2015 |
SINGLE-PHASE INDUCTION MOTOR
Abstract
A single-phase induction motor includes a stator including a
main winding with a first coil (P1a), a second coil (P1b), a third
coil (P2a) and a fourth coil (P2b). The first coil and the third
coil are manufactured from a first conductive material (2), the
second coil and the fourth coil are manufactured from a second
conductive material (3), with resistivity other than that of the
first conductive material. The first coil and the second coil are
arranged at one of the stator poles (P1) and the third coil and the
fourth coil are arranged at the opposite pole (P2). The first coil
and the fourth coil are electrically connected through a series
connection, configuring a first branch (R1). The second coil (P1b)
and the third coil (P2a) are electrically connected through a
connection in series, configuring a second branch (R2).
Inventors: |
Kalluf; Flavio J.H.;
(Joinville, BR) ; de Espindola; Aleandro Amauri;
(Joinville, BR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Whirlpool S.A. |
Sao Paulo SP |
|
BR |
|
|
Assignee: |
Whirlpool S.A.
Sao Paulo SP
BR
|
Family ID: |
49884832 |
Appl. No.: |
14/646575 |
Filed: |
November 26, 2013 |
PCT Filed: |
November 26, 2013 |
PCT NO: |
PCT/BR2013/000509 |
371 Date: |
May 21, 2015 |
Current U.S.
Class: |
310/198 |
Current CPC
Class: |
H02K 3/02 20130101; H02K
3/28 20130101; H02K 17/04 20130101; H02K 17/08 20130101 |
International
Class: |
H02K 3/02 20060101
H02K003/02; H02K 17/04 20060101 H02K017/04; H02K 3/28 20060101
H02K003/28 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 26, 2012 |
BR |
10 2012 029983.6 |
Claims
1.-16. (canceled)
17. A single-phase induction motor comprising: a stator, the stator
comprising a main winding with a first coil (P1a), a second coil
(P1b), a third coil (P2a) and a fourth coil (P2b), wherein: the
first coil (P1a) and the third coil (P2a) are manufactured from a
first conductive material (2), the second coil (P1b) and the fourth
coil (P2b) are manufactured from a second conductive material (3),
with resistivity other than that of the first conductive material
(2), the first coil (P1a) and the second coil (P1b) are arranged at
one of the stator poles (P1), the third coil (P2a) and the fourth
coil (P2b) are arranged at the pole (P2) opposite that of the first
coil (P1a) and of the second coil (P1b), the first coil (P1a) and
the second coil (P1b) comprise a number of turns equal to the
number of turns of the third coil (P2a) and of the fourth coil
(P2b), the first coil (P1a) and the fourth coil (P2b) are
electrically connected to each other through a series connection,
configuring a first branch (R1), the second coil (P1b) and the
third coil (P2a) are electrically connected through a connection in
series, configuring a second branch (R2).
18. The single-phase induction motor according to claim 17, further
comprising: an auxiliary winding (A) provided with a fifth coil
(A1) and a sixth coil (A2); wherein the first branch (R1) of the
main winding is connected electrically in series with the second
branch (R2).
19. The single-phase induction motor according to claim 17, further
comprising: an auxiliary winding (A) provided with a fifth coil
(A1) and a sixth coil (A2); wherein the first branch (R1) of the
main winding is connected electrically in parallel with the second
branch (R2).
20. The single-phase induction motor according to claim 18, wherein
the auxiliary winding (A) is configured with the fifth coil (A1)
and the sixth coil (A2) connected electrically in series and
manufactured from the same conductive material.
21. The single-phase induction motor according to claim 18, wherein
the auxiliary winding (A) is configured with the fifth coil (A1)
and the sixth coil (A2) connected electrically in series, the fifth
coil (A1) being manufactured from the first conductive material (2)
and the sixth coil (A2) being manufactured from the second
conductive material (3).
22. The single-phase induction motor according to claim 17, wherein
said motor is configured for bivolt applications, by switching the
electric connections of the branches (R1) and (R2) either in series
or in parallel.
23. The single-phase induction motor according to claim 17, wherein
the first conductive material (2) is copper and the second
conductive material (3) is aluminum.
24. The single-phase induction motor according to claim 17, wherein
the first conductive material (2) is aluminum and the second
conductive material (3) is copper.
25. The single-phase induction motor according to claim 19, wherein
the auxiliary winding (A) is configured with the fifth coil (A1)
and the sixth coil (A2) connected electrically in series and
manufactured from the same conductive material.
26. The single-phase induction motor according to claim 19, wherein
the auxiliary winding (A) is configured with the fifth coil (A1)
and the sixth coil (A2) connected electrically in series, the fifth
coil (A1) being manufactured from the first conductive material (2)
and the sixth coil (A2) being manufactured from the second
conductive material (3).
27. The single-phase induction motor according to claim 18, wherein
said motor is configured for bivolt applications, by switching the
electric connections of the branches (R1) and (R2) either in series
or in parallel.
28. The single-phase induction motor according to claim 19, wherein
said motor is configured for bivolt applications, by switching the
electric connections of the branches (R1) and (R2) either in series
or in parallel.
29. The single-phase induction motor according to claim 20, wherein
said motor is configured for bivolt applications, by switching the
electric connections of the branches (R1) and (R2) either in series
or in parallel.
30. The single-phase induction motor according to claim 21, wherein
said motor is configured for bivolt applications, by switching the
electric connections of the branches (R1) and (R2) either in series
or in parallel.
31. The single-phase induction motor according to claim 18, wherein
the first conductive material (2) is copper and the second
conductive material (3) is aluminum.
32. The single-phase induction motor according to claim 19, wherein
the first conductive material (2) is copper and the second
conductive material (3) is aluminum.
33. The single-phase induction motor according to claim 20, wherein
the first conductive material (2) is copper and the second
conductive material (3) is aluminum.
34. The single-phase induction motor according to claim 18, wherein
the first conductive material (2) is aluminum and the second
conductive material (3) is copper.
35. The single-phase induction motor according to claim 19, wherein
the first conductive material (2) is aluminum and the second
conductive material (3) is copper.
36. The single-phase induction motor according to claim 20, wherein
the first conductive material (2) is aluminum and the second
conductive material (3) is copper.
Description
[0001] The present invention relates to a single-phase induction
motor provided with a hybrid winding. The single-phase induction
motor being used on hermetic cooling compressors.
DESCRIPTION OF THE PRIOR ART
[0002] A single-phase induction motor is the type of engine most
used in household cooling applications (refrigerators, freezers,
and air-conditioners), being further used in various applications
such as washing or drying machines, fans and pumps. Single-phase
induction motors have the advantage that they can be connected to
the phase voltage of electrical networks, usually available in
residences and small rural properties, unlike three-phase motors.
Additionally, this type of motor comprises two windings arranged on
the stator, one of which is the main winding and the other is the
auxiliary winding (or starting winding), the auxiliary winding
having, as its main function, generating the turning field of the
single-phase induction motor.
[0003] The single-phase induction motors known from the prior art
have, in most cases, the main winding and auxiliary winding
manufactured from copper, having excellent thermal and electrical
properties, being an excellent electrical conductor, thus having
low electric resistivity (on the order of 1.673.times.10.sup.-6
ohmcm at 20.degree. C.
[0004] The copper's application is not limited to the use on
windings of single-phase induction motors, due to its efficiency,
resistance and reliability, copper is the most used metal in any
type of applications in which electrical or thermal conductivity is
present. This is due to the fact that copper has excellent electric
conductivity, is compatible with electric connectors and other
devices and is easy to handle, which makes the installation easier.
Additionally, copper meets the electrical specifications of most
countries.
[0005] However, copper has the disadvantage that its cost has been
increasing drastically in the last few years, and this factor has
led manufacturers of single-phase induction motors to study other
options of electric conductors. One of the options found was the
use of aluminum in the single phase induction motor windings.
Despite having 60% of the electric conductivity of copper, the use
of aluminum windings on the stator proves to be advantageous in
terms of cost, since aluminum is cheaper than copper. Besides, the
density of aluminum, being approximately 1/3 of the copper density,
reduces the weight of the windings (for a given resistance of the
coils).
[0006] Some single-phase induction motors known from the state of
art use aluminum windings, aluminum being used in the manufacture
of both the main winding and the auxiliary winding. Additionally,
it is known from the state of art single-phase induction motors
that uses a combination of two types of conductors for
manufacturing the stator windings.
[0007] As an example, one can mention patent U.S. Pat. No.
7,772,737, which describes an electric motor which the stator
windings are formed by a first electric conductor and by a second
electric conductor, the first and second electric conductors being
connected in parallel and manufactured from copper and aluminum,
respectively. Further, the US patent describes that the motor has
another winding provided with a third electric conductor and with a
fourth electric conductor, these being also connected in
parallel.
[0008] The motor described in patent U.S. Pat. No. 7,772,737 has
the disadvantage that the current flow in the motor windings is not
uniform, providing non-homogeneous heating of the motor and
harmonic torques generation, which may cause undesirable noises and
vibrations.
[0009] Further, four combinations are known regarding the type of
conductor used for making the windings of a single-phase induction
motor known from the prior art.
[0010] The first configuration would be the manufacture of the main
winding and of the auxiliary winding from copper, this
configuration is used on high-efficiency and/or high power-density
motors and has a high manufacture cost. The second configuration
makes use of the main winding made of copper and of the auxiliary
winding made of aluminum, this configuration is used when it is
possible to replace a small part of the total volume of copper by
aluminum conductors. On the other hand, the third configuration is
used when there is the possibility of replacing most of the total
volume of copper by aluminum conductors, and this configuration
consists in manufacturing the main winding from aluminum and the
auxiliary winding from copper. The fourth and last configuration
known from the prior art makes use of the main and auxiliary
winding made of aluminum, this configuration being used on motors
that do not require high efficiency and/or high power-density.
DESCRIPTION OF THE PRIOR ART BASED ON THE DRAWINGS
[0011] FIG. 1 illustrates the four electric embodiments of the
windings of a single-phase induction motor known from the prior
art. Such prior-art motors, as already mentioned, have the main
winding and the auxiliary winding manufactured using a single
conductive material (copper or aluminum) or have the main winding
manufactured from copper (or aluminum) and the auxiliary winding
manufactured from aluminum (or copper). It is noted that the
single-phase induction motors known from the prior art do not have
copper and aluminum conductors on the same winding, as proposed by
the present invention. The only known exception would be patent
U.S. Pat. No. 7,772,737, however, this patent suggests that each
branch of each winding should be formed by only one type of
material, which would impair the operation of the motor, as already
described before.
[0012] FIG. 1(a) shows the first embodiment of the windings of a
single-phase induction motor known from the prior art, as can be
observed, this motor has coils arranged at one of the poles P1 of
the stator and coils arranged at the opposite pole P2 of the
stator, wherein the first coil P1a, the second coil P1b, the third
coil P2a and the fourth coil P2b are composed of a first conductive
material, in this case copper. Additionally, the auxiliary winding
A also comprises a fifth coil A1 and a sixth coil A2 manufactured
from copper. This type of configuration is used on high-efficiency
motors and has a high manufacture cost.
[0013] As an alternative to the high manufacture cost of the
configuration shown in FIG. 1(a), one show in FIG. 1(b) the
configuration of the windings on which the coils located at pole P1
and the coils located at the opposite pole P2 continue to be
manufactured from copper. However, in this configuration the
auxiliary winding A of the induction motor is manufactured from
aluminum. Such a configuration has a slightly lower manufacture
cost as compared with the manufacture cost of the configuration
shown in FIG. 1(b).
[0014] Another possible configuration known from the prior art, is
the configuration of the windings shown in FIG. 1(c). This
configuration has the coils located at the pole P1 and the coils
located at the opposite pole P2 manufactured from aluminum, on the
other hand, the auxiliary winding A has its coils A1 and A2
manufactured from copper. In terms of cost, this configuration has
a lower manufacture cost as compared with the manufacture cost of
the configuration shown in FIG. 1(b).
[0015] FIG. 1(d) shows the configuration in which all the windings
(coils located at the pole P1 and the coils located at the opposite
pole P2 and coils of the auxiliary winding A) of the single-phase
induction motor are manufactured from aluminum,. In terms of cost,
this configuration is the one that has the lowest manufacture cost.
However, considering that the coils of the main winding comprise
75% of the total volume of the electric conductors present on the
motor winding, the number of motors which it is possible to use the
configurations shown in FIGS. 1(c) and 1(d) is very small, since
the use of aluminum is limited by the filling factor (ratio between
the area occupied by the windings and the maximum area available
for arranging them) of the single-phase induction motors.
[0016] As shown above, although the use of the largest possible
amount of aluminum is always advantageous, the use of this type of
conductor is limited by the filling factor, and when it is not
possible to increase the slots area of the blade, a part of the
conductors should remain as copper. The ideal balance of copper and
aluminum also depends on other variables, as for instance the outer
diameter of the stator, this occurs because the increase in slots
for receiving the aluminum windings would require a larger outer
diameter. In this case, one should calculate the cost of the
increment in the total amount of steel, taking into account the
increase in the slots for receiving the aluminum windings.
[0017] Among the four configurations known from the prior art and
mentioned above, the fourth configuration (main winding and
auxiliary winding made from aluminum) is the one that has the
lowest cost. However, and as already mentioned, since the main
winding is responsible for up to 75% of the total volume of the
conductor, the number of motors on which it is possible to use this
configuration is very small. So, in most cases it is not possible
to use aluminum for manufacturing the main winding, just due to the
limitations of filling the slots.
[0018] With a view to potentiate the use of aluminum on the
prior-art induction motors, the present invention makes use of a
single-phase induction motor provided with a hybrid winding, such
hybrid winding comprising aluminum conductors in conjunction with
copper conductors on the same winding branch, potentiating the
applicability of aluminum on single-phase induction motors, thus
reducing the total manufacture cost of the motor.
[0019] Further, the present invention makes use of single-phase
induction motors provided with hybrid windings, such motors may be
sized so as to be fed electrically by nominal voltage values of
115-127 VAC or 220-140 VAC.
[0020] Further, the present invention makes use of single-phase
induction motors provided with hybrid windings, such motors may be
sized to be used on bivolt motors, so that the same motor can be
fed electrically by nominal voltage values of 115-127 VAC or
220-140 VAC.
OBJECTIVES OF THE INVENTION
[0021] The present application has the objective of providing a
single-phase induction motor provided with hybrid windings.
[0022] Another objective of the present invention is to provide a
single-phase induction motor provided with a hybrid winding and
that can be fed by nominal voltage values of 115-127 VAC or 220-240
VAC.
[0023] It is also an objective of the present invention to provide
a single-phase induction motor on which the current density on the
branches and on the coils of the motor windings is homogeneous.
[0024] Finally, it is an objective of the present invention to
provide a single phase induction motor that enables the use of an
aluminum coil with a number of turns different from the number of
turns of the copper coil, without causing unbalance of current flow
or generating harmonic torques or even problems of heating or
vibrations.
BRIEF DESCRIPTION OF THE INVENTION
[0025] The objectives of the invention are achieved by providing a
single-phase induction motor comprising a stator, the stator
comprising a winding with a first coil P1a, a second coil P1b, a
third coil P2a and a fourth coil P2b. The first coil P1a and the
third coil P2a are manufactured from a first conductive material 2.
The second coil P1b and the fourth coil P2b are manufactured from a
second conductive material 3, with resistivity different from the
first conductive material 2. The single-phase induction motor is
configured so that the first coil P1a and the second coil P1b are
arranged at one of the poles P1 of the stator. The third coil P2a
and the fourth coil P2b are arranged at the pole P2 opposite that
of the first coil P1a and of the second coil P1b. The first coil
P1a and the fourth coil P2b are electrically connected in series,
configuring a first branch (R1). The second coil P1b and the third
coil P2a are electrically connected through a connection in series,
configuring a second branch R2.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] The present invention will now be described in greater
detail with reference to the attached drawings, in which:
[0027] FIG. 1 illustrates the electric connections of a
single-phase induction motor known from the state of art;
[0028] FIG. 2 is a representation of the electric connection of a
single-phase induction motor as proposed in the present
invention;
[0029] FIG. 3 is a representation of the electric connection of one
of the single-phase induction motor windings as proposed by the
present invention with the series connection of the R1 and R2
branches.
[0030] FIG. 4 is a representation of the electric connection of one
of the single-phase induction motor windings as proposed by the
present invention with the parallel connection of the R1 and R2
branches.
DETAILED DESCRIPTION OF THE INVENTION
[0031] As can be observed in FIG. 2, one represents a preferred
electrical connection of the single-phase induction motor provided
with a stator as proposed in the present invention. Such a
single-phase induction motor comprises a main winding with fourth
coils, a first coil P1a, a second coil P1b, a third coil P2a and a
fourth coil P2b, wherein the first coil P1a and the third coil P2a
are preferably manufactured from a first conductive material 2,
this material being copper. On the other hand, the second coil P1b
and the fourth coil P2b are preferably manufactured from a second
conductive material 3, this material being aluminum.
[0032] The main winding is configured so that the first coil P1a
and the second coil P1b are at one of the poles P1 of the stator,
and the third coil P2a and the fourth coil P2b are at the opposite
pole P2 of the stator. The electric connection in series of the
first coil P1a and of the fourth coil P2b configures a first branch
R1 of the single-phase induction motor of the present invention. On
the other hand, the electric connection in series of the second
coil P1b and of the third coil P2a configures a second branch R2.
Such form of electric connection of the coils of the branches R1
and R2 configures a hybrid crossed connection of the induction
motor described in the present invention and shown in FIG. 2.
[0033] Further, the single-phase induction motor proposed in the
present invention guarantees the balance of the inductances and
resistances and, as a result, guarantees that the current in the
motor winding will be the same one. Additionally, the single-phase
induction motor enables the use of a coil made of aluminum with a
number of turns different than the number of turns of the copper
coil, without causing unbalance of current flow or generating
harmonic torques.
[0034] As can be better observed in FIG. 2, the single-phase
induction motor further comprises an auxiliary winding A. In this
preferred embodiment, the auxiliary winding A comprises a fifth
coil A1 and a sixth coil A2 electrically connected in series and
manufactured from the same material. It should be pointed out that,
in an additional embodiment of the present single-phase induction
motor, the auxiliary winding A might have the fifth coil A1
manufactured from copper and the sixth coil A2 manufactured from
aluminum, or vice-versa.
[0035] Additionally, present embodiment can be used for
constructing bivolt single-phase induction motors, that is,
configured to be fed electrically by nominal voltage values of
115-127 VAC or 220-240 VAC, without the need to alter the number of
turns or the diameter of the wires. In this case, for the higher
nominal voltage (220-240 VAC), one should connect the branches R1
and R2 electrically in series, as shown in FIG. 3. On the other
hand, for the lower nominal voltage (115-127 VAC), one should
connect them in parallel, as shown in FIG. 4.
[0036] FIG. 3 shows the scheme of electrical connections that
should be carried out in the case of nominal voltage in the range
220-240 VAC. As can be observed, the branch R1, comprising the
first coil P1a and by the fourth coil P2b, is electrically
connected in series with the branch R2, comprising the second coil
P1b and by the third coil P2a. In this preferred example of the
induction motor, the first coil P1a and the third coil P2a are
manufactured from a first material 2, this material being copper.
On the other hand, the second coil P1b and the fourth coil P2b are
manufactured from a second material 3, this material being
aluminum.
[0037] In the case of feeding with nominal voltage in the range of
220-240 VAC, the connection of the branches R1 and R2 in series
enable the balance of voltage between such branches, dividing the
voltage exactly by half.
[0038] FIG. 4 shows the scheme of electric connections that should
be carried out in the case of nominal voltage in the range of
115-127 VAC. As can be observed, the branch R1, comprising the
first coil P1a and the fourth coil P2b, is electrically connected
in parallel with the branch R2, comprising the second coil P1b and
the third coil P2a. The first coil P1a and the third coil P2a are
manufactured from copper and the coils P1b and P2b are manufactured
from aluminum.
[0039] A preferred example of embodiment having been described, one
should understand that the scope of the present invention embraces
other possible variations, being limited only by the contents of
the accompanying claims, which include the possible
equivalents.
* * * * *